Resolving the Discrepancy of 135 MeV $pd$ Elastic Scattering Cross Sections and Relativistic Effects

Three precise measurements for elastic $pd$ scattering at $135\mathrm{MeV}/A$ have been performed with the three different experimental setups. The cross sections are described well by the theoretical predictions based on modern nucleon-nucleon forces combined with three-nucleon forces. Relativistic Faddeev calculations show that relativistic effects are restricted to backward angles. This result supports the two measurements recently reported by RIKEN and contradicts the KVI data.

Figure 1

Differential cross section for elastic $Nd$ scattering at $135\mathrm{MeV}/\mathrm{\text{nucleon}}$. The light shaded band contains $NN$ force predictions (AV18, CDBonn, Nijmegen I and II). The dark shaded band results when they are combined with the TM99 $3N\mathrm{F}$. The solid line is the $\mathrm{AV}18+\mathrm{\text{Urbana IX}}$ prediction. The dashed and dotted lines are the results of relativistic and nonrelativistic Faddeev calculations based on the $NN$ forces AV18. The symbols are data from different measurements (see text).